class_docstr: Legacy Delta XYWH BBox coder used in MMDet V1.x.
  
  Following the practice in R-CNN [1]_, this coder encodes bbox (x1, y1, x2,
  y2) into delta (dx, dy, dw, dh) and decodes delta (dx, dy, dw, dh)
  back to original bbox (x1, y1, x2, y2).
  
  Note:
      The main difference between :class`LegacyDeltaXYWHBBoxCoder` and
      :class:`DeltaXYWHBBoxCoder` is whether ``+ 1`` is used during width and
      height calculation. We suggest to only use this coder when testing with
      MMDet V1.x models.
  
  References:
      .. [1] https://arxiv.org/abs/1311.2524
  
  Args:
      target_means (Sequence[float]): denormalizing means of target for
          delta coordinates
      target_stds (Sequence[float]): denormalizing standard deviation of
          target for delta coordinates
code: def __init__(
      self,
      target_means=(0.0, 0.0, 0.0, 0.0),
      target_stds=(1.0, 1.0, 1.0, 1.0),
  ):
      super(BaseBBoxCoder, self).__init__()
      self.means = target_means
      self.stds = target_stds
  
file_path: insightface/detection/scrfd/mmdet/core/bbox/coder/legacy_delta_xywh_bbox_coder.py
imports: import numpy
  import torch
  from ..builder import BBOX_CODERS
  from .base_bbox_coder import BaseBBoxCoder
label_desc: Use image node_id 1 to create a new LegacyDeltaXYWHBBoxCoder object from inherited base classes: BaseBBoxCoder with example: obj = LegacyDeltaXYWHBBoxCoder(target_means, target_stds)